Layer-0, the fiber optic physical network layer, is the foundation of the global communications infrastructure for transmitting voice, data and video traffic. The management of this portion of the network is a labor-intensive process involving manual record keeping, testing, debugging and cable patching. According to BICSI News, up to 70% of network downtime is the result of cabling problems. Network Systems DesignLine [Mar. 14, 2007] reported that “the number one cause of fiber optic network downtime is equipment damage resulting from human error, either through rough handling or improper cable routing”.
The challenges to operate large-scale networks are currently being addressed in part by automating the higher network layers, in particular, layer-1 through layer-7. Since these particular layers are comprised of electronic and software network elements, they are readily monitored by network management systems. In contrast, optical interconnect elements within layer-0, being purely optical and electrically passive, comprise an invisible infrastructure whose status is often neglected and management is highly manual. This situation is exacerbated by the fact that layer-0, the “physical layer”, is the largest in terms of the number of network elements, including all the fiber optic patch-panels, distribution frames and cables that link routers, switches and multiplexers.
Technologies to automate the management and monitoring of the communications infrastructure are of prime importance. For instance, Radio Frequency Identification (RFID) technology has the potential to reduce the challenges of managing a large inventory of physical network elements. In the “RFID Handbook” (1st Edition, 1999) by B. Finkenzeller, an overview of the various electronic identification techniques are described.
Regarding specific RFID applications to communications, U.S. Pat. No. 6,808,116 to Eslambolchi et al. describes fiber optic patch-cords wherein an RFID tag is integrated with a fiber connector. Kozischek et al. in US 2009/0097846 describes the use of one or more mobile RFID readers to read and write to tags in the general vicinity of the reader. Cook describes in US 2008/0204235 the use of fiber optic cables in which a multiplicity of RFID tags are disposed along the length of each fiber optic cable.
In these prior art RFID systems, a single reader interrogates an extended volume occupied by potentially a large number of closely spaced tags. To aid in the identification of a specific cable, Downie et al. in US 2008/0100467 describes the integration of an RFID tag and physical switch on a fiber optic connector. The depression of the switch activates the particular tag associated with that connector, so that only its unique RF identifier is read by a global RFID reader. This is a manual approach to resolve the crosstalk that arises upon interrogating a panel with a multiplicity of closely spaced RFID tags.
Furthermore, techniques to extend the range of a portable RFID reader has been described by R. Stewart in US 2009/0015383, entitled “Inductively Coupled Extension Antenna for a Radio Frequency Identification Reader”. Stewart describes a portable RFID reader with a rigid, attachable extension tube antenna that is inductively coupled to the portable RFID reader.
In an alternative RFID approach, the translation and transmission of RFID signals into the optical domain is described by Easton in US 2007/285239. The electronic RFID signal is converted to optical domain by an E-O converter and transported over fiber to a distant reader.
While these various prior art RFID systems and devices can assist in the inventory management of physical connections, they nonetheless require significant manual intervention to determine and relate the network topology map to the physical interconnection database. Significant network operations advantages are derived by providing automated approaches to these highly manual processes.